How metallylenes activate small molecules

Abstract

Quantum chemical analyses reveal how model metallylene catalysts activate H2. This is the first step towards the rational design of metallylenes for the activation of small molecules and subsequent reactions.

Chemical reactivity from an activation strain perspective

“…With the help of the activation strain model, we are able to quantify the factors that determine the trends in reactivity of the activation of dihydrogen (H 2 ) by various metallylenes H 3 C–E–X, where E = C, Si, Ge, Sn, and X = NMe 2 , PMe 2 , AsMe 2 ( Scheme 2 ). 13 These model metallylenes were chosen because they closely resemble experimentally accessible metallylene species. 34 a , c We found that upon changing the central metallylene atom down in Group 14, from carbon to tin, while keeping the ligand unchanged, systematically increases the H 2 activation barrier.…”

“…First, we will discuss the ASM in great detail by describing the origin of the various energy terms within this model. Thereafter, we showcase some recent advances of applying the ASM to various chemical problems, such as the competition between S N 2 and E2 reaction, 12 how metallylenes activate small molecules, 13 and the cycloaddition reactivity of cycloalkenes, cycloalkynes, and cycloallenes. 14 …”

“…First, we will discuss the ASM in great detail by describing the origin of the various energy terms within this model. Thereafter, we showcase some recent advances of applying the ASM to various chemical problems, such as the competition between S N 2 and E2 reaction, 12 how metallylenes activate small molecules, 13 and the cycloaddition reactivity of cycloalkenes, cycloalkynes, and cycloallenes. 14 The activation strain model (ASM), also known as the distortion/interaction model, 15 is a fragment-based approach to understand chemical reactivity in terms of the properties of the original reactants (e.g., sterics, rigidity, bonding capability) and the characteristics of reaction mechanisms (e.g., extent of distortion reactants must undergo).…”

Structural, Electronic, Reactivity, and Conformational Features of 2,5,5-Trimethyl-1,3,2-diheterophosphinane-2-sulfide, and Its Derivatives: DFT, MEP, and NBO Calculations

“…Since the hyperconjugation of two electrons and orbitals occurs, stabilization is significant [40]. The effect of the molecule geometry on the energy gap, the ability of the empty orbital to receive, and the ability of the filled orbital to donate are essential parts of this scenario [41,42]. The resonance values of the energies related to naxX ® σ*P-Selectron delocalization are 12.48, 9.86, and 8.12 kcal mol −1 for the ax.…”

Origin of Ligand Effects on Stereoinversion in Pd-Catalyzed Synthesis of Tetrasubstituted Olefins

“…In this work, we first elucidated the detailed reaction mechanism by investigating multiple competing pathways. Using the distortion/interaction-activation strain model and energy decomposition analysis (EDA), which have been utilized to successfully explain and predict the origins of reactivity and selectivity in many reactions, we then identified the dominant factors for controlling the stereoselectivity with different phosphine ligands.…”